Combined sewer systems provide a collection network of pipes within a municipal wastewater treatment system for conveying wastewater to water treatment plants. Wastewater is a product of activities of daily living and industrial activities. From a residential perspective, wastewater comes from activities like bathing, toilet flushing, laundering, and dishwashing to name a few. Industrially, wastewater is generating by manufacturing and other business sources that use water in their processes, or in their employees activities of daily living, and such processes causes the water disposed of to be unclean. Conceptually, wastewater is divided into two broad categories: gray water is from the above kinds of activities other than toilets and kitchen sinks. Blackwater is generally thought of as wastewater from toilets and kitchen sinks, although some states limit the definition to sewage (wastewater coming from toilets).
A combined sewer system is a municipal wastewater collection system that conveys wastewater and storm water through a pipe system to a treatment plant. The contents of a combined sewer system are both human-generated (wastewater) and naturally-occurring (storm water). A sanitary sewer system is a municipal wastewater collection system that also conveys limited amounts of infiltrated ground water and storm water to a treatment plant. Sanitary sewer systems may have a separate storm sewer system to collect and convey runoff from rainfall and snowmelt. For brevity, where the present descriptions use the term “combined sewer system,” the disclosed embodiments likewise apply to sanitary sewer systems.
Wastewater is introduced to a combined sewer system via pipes connected to buildings and residences. Storm water is introduced to the combined sewer system through drains and other inlets that communicate with the surface of the ground. Treatment of wastewater includes both primary and secondary treatment. Primary treatment involves removing large solids and sludge and may include the use of mechanical screens to trap such matter. Secondary treatment involves pathogen removal and breaking down the biological matter in the treated water.
However, the capacity of combined sewer systems to handle combined wastewater and storm water is limited by the finite volume of the pipes making up these systems. When the combined volume of wastewater and storm water entering a system exceeds that finite capacity, for example during and after periods of heavy precipitation, it produces overflow. Instead of allowing the excess to backup into residences and businesses, most combined sewer systems utilize overflow pipes for discharging untreated wastewater directly to natural waterways (e.g., rivers, streams, lakes, estuaries, and coastal waters) when the combined volume of wastewater and storm water exceeds the capacity of the combined sewer system. Such discharges, or combined sewer overflows, often include a combination of storm water runoff as well as residential, commercial, and industrial wastewater, which introduces human and industrial wastes and pollutants into the environment.
The wastes and pollutants that are introduced carry environmental and health consequences, and are the subject of regulatory efforts. In this country, municipalities have secured permits establishing discharge points for combined sewer overflows at thousands of sites. When the amount of discharge at a site(s) exceeds the volume established by permit, a municipality is subject to fines and consent decrees as a means to encourage better management of the combined sewer system.
The success of attempts to control what enters combined sewer systems has been mixed, and many of the municipalities have had to enter into governmental consent decrees aimed at reducing the effects from combined sewer overflows. Some attempts have involved surface diversion means to reduce or slow the volume of storm water that enters the combined sewer system, examples of which include bioretention cells and soil filtration systems. Others have attempted to regulate the progress of the combined wastewater and storm water within the combined sewer system, to increase the period of time it takes for heavy volumes to reach the treatment plant. However, little attention has been paid to reducing the volume of wastewater entering the combined sewer system in the first place. The volume of wastewater produced is a function of human activity. By encouraging or causing the modification of human activity during periods during and after heavy precipitation, as rain is falling or snow is melting, it is possible to reduce the volume of wastewater entering a combined sewer system during those critical times. With proper notification, responsible users will reduce their usage of appliances and machines that generate wastewater for an appropriate period of time until storm water recedes and the combined sewer system returns to pre-storm carrying volume.
Accordingly, present embodiments result in notifications transmitted to appliances, machines, and other devices. Users will see the notifications on a display, and will be able to make informed choices about their wastewater-generating activities, resulting in reduced volumes of wastewater entering combined sewer systems during times when such systems are most affected by heavy precipitation. Additional features and advantages will be evident from reviewing these descriptions and teachings.